For fetch spec (http://fetch.spec.whatwg.org/#fetch-method), fetch() method is on WorkerGlobalScope. The globals Dedicated & SharedWorkerGlobalScope inherit from it. WebIDL codegen traceback: 0:16.01 Traceback (most recent call last): 0:16.01 File "/usr/lib64/python2.7/runpy.py", line 162, in _run_module_as_main 0:16.01 "__main__", fname, loader, pkg_name) 0:16.01 File "/usr/lib64/python2.7/runpy.py", line 72, in _run_code 0:16.01 exec code in run_globals 0:16.01 File "/home/nikhil/mozilla-central-fetch/python/mozbuild/mozbuild/action/webidl.py", line 17, in <module> 0:16.01 sys.exit(main(sys.argv[1:])) 0:16.01 File "/home/nikhil/mozilla-central-fetch/python/mozbuild/mozbuild/action/webidl.py", line 13, in main 0:16.01 manager.generate_build_files() 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/mozwebidlcodegen/__init__.py", line 263, in generate_build_files 0:16.01 written, deps = self._generate_build_files_for_webidl(filename) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/mozwebidlcodegen/__init__.py", line 464, in _generate_build_files_for_webidl 0:16.01 root = CGBindingRoot(self._config, binding_stem, filename) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 11341, in __init__ 0:16.01 cgthings.extend([CGDescriptor(x) for x in descriptors]) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 10277, in __init__ 0:16.01 cgThings.append(CGGeneric(define=str(properties))) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 2309, in __str__ 0:16.01 define += str(getattr(self, array)) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 1858, in __str__ 0:16.01 self.usedForXrays()) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 2168, in generateArray 0:16.01 condition, specData, doIdArrays) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 1946, in generatePrefableArray 0:16.01 specs.append(specTemplate % getDataTuple(member)) 0:16.01 File "/home/nikhil/mozilla-central-fetch/dom/bindings/Codegen.py", line 2148, in specData 0:16.01 accessor) 0:16.01 TypeError: fetch returns a Promise but needs special generic ops?

Yeah, we just need to add the support for this; I didn't add it initially when landing the Promise stuff because we had no consumers at the time. Do you want to try doing it, or should I do it?

Do I need to preserve the callee the way GenericPromiseReturningBindingMethod does? In that case, where do I put the code to preserve the callee in Codegen.py?

Comment on attachment 8438036 [details] [diff] [review] Add support for Promise returning methods on globals. > Do I need to preserve the callee the way GenericPromiseReturningBindingMethod > does? Yes, because CallArgs stores callee and rval in the same place. So once someone does rval() you can't even do args.callee() without asserting... > In that case, where do I put the code to preserve the callee in Codegen.py? Putting it at the top of your new generate_code output and also at the top of the unwrapFailureCode block should work fine, I expect. >+ args.rval());\n"""% Space before '%', please. r=me with the nits fixed and the callee/rval thing addressed.

As discussed on IRC, we agreed to use the callArgs to save the callee right at the beginning of the function to avoid any "should work fine, I expect" moments!